M/s Nanotech, Inc. has developed a water-based nanotechnology coating product called Nansulate that can literally be applied to any surface to reduce heat transfer. In buildings it can be applied on external walls to keep it cool. It acts as thermal insulation and can also prevent corrosion, offer flame resistance, cut down on mold growth and encapsulate lead and other harmful substances often found in buildings, preventing them from leaching into the ground. On metallic surfaces it can be used to reduce heat conduction and so on. 

http://www.nansulate.com/
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